Screening Tool Reveals Two Multiple Sclerosis Types
WEDNESDAY Sept. 26, 2012 -- An experimental screening technique finds that multiple sclerosis patients have two different molecular "signatures" that reflect disease severity.
This suggests that doctors might one day use this tool to help determine who has a more aggressive form of MS and might need earlier treatment with stronger medications, researchers report.
"This study shows there is evidence that we can begin to identify subsets of MS patients, and that we're moving ever-so-slowly to personalizing MS care," said study author Dr. Philip De Jager, an associate professor at Harvard Medical School and an associate neurologist at Brigham and Women's Hospital in Boston.
But this screening tool "is not ready for the clinic at this point. It needs to be validated in another trial," De Jager said. He envisions that this test would be one component of a number of tests doctors could use to generate risk estimates.
Results of the study are published in the Sept. 26 issue of Science Translational Medicine.
About 400,000 Americans have MS, a chronic, sometimes disabling disease that affects the central nervous system. The central nervous system includes the brain, spinal cord and optic nerves, according to the National Multiple Sclerosis Society. MS symptoms may include fatigue, numbness in the limbs, balance and coordination problems, bladder or bowel dysfunction, vision problems, pain, and even paralysis.
A few treatment options exist for one type of the disease, but no single therapy helps everyone with MS, and there is no cure.
The four types of MS include relapsing-remitting, primary progressive, secondary progressive and progressive-relapsing, the MS society says. About 85 percent of people with MS have the relapsing-remitting form of the disease, and the available treatments are for this form of the disease.
It's often difficult to diagnose MS, and it can take even longer to figure out which type someone has. In addition, doctors have no way to predict which patients will respond to a particular drug.
"Right now, we typically start with first-line drugs that are moderately effective, but safe. If someone doesn't respond, we move on to stronger drugs that tend to be more effective, but have more adverse events," said De Jager. "If we knew that someone had an aggressive form of the disease, we'd know that they're less likely to derive benefit from first-line treatments."
The experimental screening test examines peripheral blood cells (blood obtained from locations away from the heart) on a molecular level. These blood cells are important because they contain immune cells that contribute to MS disease activity, De Jager said.
For the current study, the researchers analyzed blood from 363 people with relapsing-remitting MS who hadn't received treatment. The researchers didn't know ahead of time how aggressive their disease was.
They found two distinct subsets of MS, dubbed MSa and MSb. MSa appeared to be more aggressive, and these are the people who might benefit from earlier treatment with stronger drugs.
The researchers also performed the analysis on 94 people treated with glatiramer acetate and 128 people treated with interferon-B. Again, the researchers found the two subsets, and it didn't appear to make much difference which drug someone was taking.
Timothy Coetzee, chief research officer at the National Multiple Sclerosis Society, said if this research is validated, he could envision it being used to help develop more targeted therapies. It could also be useful in clinical trials to help evaluate how well a drug is performing, he said.
"What we don't know and what we need to get better at is predicting the course of MS. We just don't have the equivalent of a cholesterol test for MS, and that's the kind of information patients want to know," Coetzee said. "They want to know what test can you give me that will help me understand what my future will look like."
De Jager said the next step is to confirm their findings with another trial, and that the next trial will test blood samples from multiple time points rather than a single time point. This is important because the nature of MS is that at some points it's inactive. So, the researchers have to be sure that they've captured two distinct subsets of people with MS, and not the disease at two different time points.
Learn more about multiple sclerosis and the different types, visit the National Multiple Sclerosis Society.
Posted: September 2012